Feb.5 (GMM) Formula one risks losing yet another manufacturer if it does not act appropriately amid the engine freeze. That is the view of Christian Horner, boss of the Renault-powered Red Bull team.

Amid suggestions that Mercedes' V8 unit sped ahead of its rivals in 2009 despite the mandated development moratorium, pressure was exerted on the FIA to allow the lagging engine makers to catch up.

But when the FIA said it would only allow the best engines to de-tune for 2010, no agreement on equalisation within the teams was reached.

It is even believed that Renault, although perhaps not as powerful as the Mercedes and Ferrari, could be at an advantage with the refuelling ban this year, because it is very efficient.

"The FIA has all the data in hand to decide upon an adjustment of the engines," Horner told Germany's Auto Bild motorsport.

The engine freeze rules do not actually stipulate the need for performance equality, but after the loss of Honda, BMW and Toyota, there are now just four engine manufacturers in F1, including the returning Cosworth.

"It would be a disaster to lose another engine manufacturer at the end of the year because they cannot compete with the others," Horner added.

"The rules for the development of the chassis are so strict that the engine plays an ever more important role," he said.